How Long Does It Take for a Dropped Packet to Hit the Ground?

[shehri]

Homework Statement

A Helicopter is vertically moving upward with speed of 8m/s.At a height of 122.8m from ground,a packet is fallen from the Heli window.How much time would the packet take for hitting to ground?

Homework Equations

vf=vi+gt.
S=vit+1/2gt^2
2aS=vf^2-vi^2

The Attempt at a Solution

 

[chanvincent]

You have the initial speed of the packet, also the distance from the ground, and you are required to find t,
Which of the three equations you going to use?
a.) vf=vi+gt.
b.) S=vit+1/2gt^2
c.) 2aS=vf^2-vi^2

 

[cristo]

Homework Statement

A Helicopter is vertically moving upward with speed of 8m/s.At a height of 122.8m from ground,a packet is fallen from the Heli window.How much time would the packet take for hitting to ground?

Homework Equations

vf=vi+gt.
S=vit+1/2gt^2
2aS=vf^2-vi^2

The Attempt at a Solution

Well... what have you tried? Show your work please.